function SuperType() {
    this.property = true;
}
SuperType.prototype.getSuperValue = function () {
    return this.property;
}
function SubType() {
    this.subproperty = false;
}
SubType.prototype = new SuperType();
SubType.prototype.getSubValue = function () {
    return this.subproperty;
}
// SubType.prototype.getSuperValue=function(){
//     return false;
// }
SubType.prototype={
    getSubValue:function(){
        return this.subproperty;
    },
    someOtherMethod: function () {
        return false;
    }
}
let instance=new SubType();
console.log(instance.getSuperValue());